"Although the .NET vs. Java war is basically over for control of the Windows desktop, where .NET is sure to become the managed language of choice for new Windows desktop applications, there is a new battle brewing. That battle is for the Linux desktop. Now that Java has been open sourced under the GPL, even the most strict of the 'free software only' distributions can start bundling it and integrating it into their Linux distributions out of the box."

I would add the desktop version (not the online version) of ThinkFree Office to that list, which in my mind, is a shining example of a truly excellent desktop Java application. It's responsive, fast, and looks great.